The Drigganita system is in contrast to the method followed by some other almanac makers who use the values given in the ancient astronomical treatise known by the name Surya Siddhanta.
[2] In the history of astronomy in India, two different Drigganita systems have been introduced at two different points of time and at two different geographical locations.
[1][3] In the nineteenth century, a second Drigganita system was introduced by Chinthamani Ragoonatha Chary (1822 – 5 February 1880) an Indian astronomer attached to the then Madras Observatory.
Also the values of the sines of arc of anomaly (manda-jya) and of commutation (sighra-jya) are revised and are given for intervals of 6 degrees.
[1] Chintamani Ragoonathachary, a native astronomer took the initiative to modify and publish a new almanac and thereby introduced a change in the calendrical system followed in the Tamil region.